Pulmonary vein stent for treating atrial fibrillation

Abstract

An apparatus and method for treating atrial fibrillation is described that uses a vascular stent deployed within the pulmonary veins of the left atrium. The stent may be used alone or in combination with chemical, thermal, electrical, or radioactive energy sources to ablate myocardial tissue residing in the pulmonary veins. The targeted myocardial tissue in the pulmonary veins will have been identified as the source of initiation and/or sustenance of atrial fibrillation. Ablation therapy using the pulmonary venous stent stops discharges from ectopic foci in the vein or alternatively stops impulses from reaching the left atrium. The deployed stent can then be left in place to prevent stenosis of the vein.

What is claimed is: 
     
       1. A method, comprising:
 introducing a stent catheter having a stent mounted thereon into the left atrium of a patient; 
 deploying the stent into a pulmonary vein, the superior vena cava, or the inferior vena cava by inflating a balloon at the distal end of the stent catheter to expand the stent within the vein; and, 
 transmitting electrical energy from an electrode mounted on a surface of the balloon to a plurality of electrodes separated by insulation on a surface of the stent to produce a plurality of discrete and unconnected lesions in the tissue surrounding the stent. 
 
     
     
       2. The method of  claim 1  further comprising leaving the stent in the vein after production of the lesions to prevent stenosis. 
     
     
       3. The method of  claim 1  wherein the transmitted electrical energy is direct current. 
     
     
       4. The method of  claim 1  wherein the transmitted electrical energy is alternating current. 
     
     
       5. The method of  claim 1  wherein the plurality of electrodes separated by insulation is a plurality of patch electrodes located on the surface of the stent for producing a plurality of discrete lesions in the tissue surrounding the stent. 
     
     
       6. The method of  claim 1  wherein the plurality of electrodes separated by insulation is a plurality of spaced apart annular electrodes located on the surface of the stent for producing a plurality of discrete and unconnected circumferential lesions in the tissue surrounding the stent. 
     
     
       7. The method of  claim 1  further comprising:
 introducing the catheter into a peripheral vein and then advancing through the vena cava and into the right atrium; 
 positioning the catheter against the fossa ovalis in the atrial septum and advancing a needle or trochar distally through a lumen of the stent catheter and out the distal end to puncture the fossa ovalis; and, 
 passing the catheter through atrial septum to reach the left atrium. 
 
     
     
       8. The method of  claim 1  further comprising accessing a peripheral artery and advancing the catheter into the aorta, around the aortic arch, into the left ventricle, and then into the left atrium through the mitral valve. 
     
     
       9. An apparatus, comprising:
 a stent catheter having a stent mounted thereon; 
 a balloon at the distal end of the stent catheter to expand the stent within a vessel; 
 a plurality of electrodes separated by insulation on a surface of the stent; 
 an electrode mounted on a surface of the balloon for transmitting electrical energy to the plurality of electrodes to thereby produce a plurality of discrete and unconnected lesions in the tissue surrounding the stent. 
 
     
     
       10. The apparatus of  claim 9  wherein the plurality of electrodes separated by insulation is a plurality of patch electrodes located on the surface of the stent for producing a plurality of discrete lesions. 
     
     
       11. The apparatus of  claim 9  wherein the plurality of electrodes separated by insulation is a plurality of annular electrodes located on the surface of the stent for producing a plurality of discrete and unconnected circumferential lesions. 
     
     
       12. The apparatus of  claim 9  wherein the stent is flared at one end for extending beyond the ostium of a vein when deployed.